The present invention relates to a machine for wet treatment in rope form, for textile materials, for example a machine for the dyeing of fabrics, more specifically a machine of elongate shape. The invention will be more particularly described hereafter within the framework of its application to a dyeing machine.
There are various types of dyeing machine, in particular beam-dyeing autoclaves, with which the present invention is not concerned, and machines for dyeing in rope form, more particularly under consideration here, in which the fabric to be treated forms a xe2x80x9cropexe2x80x9d closed on itself, which follows a looped circuit within the machine, at the same time passing through a transport zone and a storage zone. The machines for dyeing in rope form comprise, in turn, machines of which the vat for storing the fabric is of round general shape and other machines of which the vat for storing the fabric is of elongate shape.
In the machines of round shape, the fabric is driven by mechanical, hydraulic or aeraulic means. The drive may also be carried out by a combination of the abovementioned means. Examples of such machines which may be cited here are U.S. Pat. Nos. 3,921,420 and 3,949,575 or European Patent Application No. 0334749. These machines have, in general terms, the disadvantage that the fabric is crushed in the storage zone.
In the machines of elongate shape, the fabric storage vat is horizontal or of a shape and orientation close to the horizontal, and the circuit of the fabric is closed above or below the horizontal storage zone. The fabric is driven by mechanical or hydraulic means or by a combination of these two types of means; as regards the hydraulic means, these involve a drive system employing the dyeing bath itself which is suitably set in motion. The essential feature of the machines of elongate shape is that the textile material is stored in folds, without crushing, or, more precisely, that each elementary length of fabric undergoes the same crushing during the entire storage, in contrast to a machine of round shape, in which the fabric undergoes different compression, depending on whether it is located at the start, in the middle or at the end of the storage zone. Examples of machines of elongate shape which may be cited here are German Patent Application No. 2207679 and U.S. Pat. No. 3,802,840.
All these known machines still give rise to faults on the fabrics to be dyed, in particular faults of the xe2x80x9cpillxe2x80x9d or xe2x80x9ccrow""s footxe2x80x9d type or faults of the dye xe2x80x9ccreasexe2x80x9d type. These faults are found with increasing frequency on account of the new treated textile materials which comprise elastomeric threads in the weft direction and/or warp direction in increasingly large proportions.
The object of the present invention is to eliminate this type of fault, while making it possible to speed up the treatment of some of these textile materials.
For this purpose, the subject of the invention is essentially a machine for wet treatment in rope form, of the type including a machine of elongate shape, comprising a horizontally elongate vat, in which is formed a zone for the storage in folds of the fabric to be treated, and hydraulic and/or mechanical means for driving the fabric, which are placed preferably at the start of a transport tube or duct provided for returning the fabric from the front end of the vat toward the rear end of this vat, the fabric forming a rope closed on itself, this machine being characterized in that means for injecting a gas stream in contact with the fabric are provided within said vat or in the surroundings of this vat, the means for injecting a gas stream being located, in the direction of travel of the fabric, between the point where this fabric returns to the storage zone and the hydraulic and/or mechanical means for driving the fabric.
Thus, the invention proposes a machine for wet treatment, for example dyeing, of elongate shape, in which a system for the injection of gas, such as air, is installed, this system being arranged in the path of the fabric, within the fabric storage vat or in its immediate vicinity, and taking action after the fabric has been transported from the front of the machine toward the rear and before said fabric is taken up by the system for the hydraulic drive of the machine (if appropriate, assisted by mechanical means).
The choice of an elongate machine eliminates the faults attributable to the crushing of the textile material, and the gas injection system eliminates the dye xe2x80x9ccreasesxe2x80x9d by virtue of its function of spreading and drying the material. In this respect, it will be noted that, here, the gas injection means do not ultimately drive the fabric forward, but essentially unfold it and dry it. After having been spread in this way, the textile material is once again returned to rope form and stored in folds, but in folds different from those of the preceding lay, and so on and so forth. At the end of the complete treatment cycle, which may last from a few minutes to eight hours or more, the fabric will have changed folds at each lay and will therefore be treated in a perfectly uniform manner without xe2x80x9ccreasesxe2x80x9d. The action of the gas stream makes it possible, here, to reduce very significantly the times for treating the materials, while improving the treatment quality, in particular the stability of the materials during use, including modern textile fibers which present problems in this respect (viscose which is produced in solutions based on recovered solvent and which is used alone or in a mixture with other materials).
Adapting the volume and pressure of the injected gas makes it possible to adjust the treatment to the material and thereby succeed in this treatment.
According to one embodiment of the invention, the means for injecting a gas stream are located, within the storage vat, in the region of the rear end of this vat, along the path of the fabric, downstream of the issue of the tube or duct for returning the fabric to the vat. A deflecting roller, driven in rotation or free, can be arranged on the path of the fabric, between the issue of said return tube or duct and the means for injecting a gas stream.
According to another embodiment of the invention, the return tube or duct is prolonged by a tube, in particular a bent tube, within the storage vat, the latter tube having its downstream end connected directly to the means for injecting a gas stream.
Advantageously, said means for injecting a gas stream comprise a gas injection nozzle placed within the vat and connected to a fan located outside this vat, the fan comprising at least one gas intake in the upper part of said vat. Preferably, a plurality of gas intakes distributed over the length of the vat will be provided for the fan.
According to another possibility, the means for injecting a gas stream are located outside the vat, in particular on a branch duct through which the fabric to be treated passes.